


Of Angels and Monsters

by flamingburningfandomtrash



Category: Undertale (Video Game)
Genre: Cussing, F/M, Fluff, Possessive Sans (Undertale), Protective Sans (Undertale), Reader-Insert, Target, Underfell Post-Pacifist, Underfell Sans (Undertale), creepy guys
Language: English
Status: Completed
Published: 2020-02-23
Updated: 2020-02-23
Packaged: 2021-02-28 06:33:51
Rating: Not Rated
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,288
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/22869415
Author URL: https://archiveofourown.org/users/flamingburningfandomtrash/pseuds/flamingburningfandomtrash
Summary: A simple shopping trip turns into an all out fluff fest.With creeps, as per usual.
Relationships: Underfell Sans/Reader
Comments: 12
Kudos: 154





	Of Angels and Monsters

**Author's Note:**

> SO.  
> uh.  
> My writer's block is getting worse.  
> Maybe there should be a term for lack of writer's motivation and focus.
> 
> But, good news in the end notes~~~

“So, I’m warning you for the day,” you say, glancing over at Sans as you zip up your jacket. “Not wearing a shirt under this thing, and you have to promise to just, stay chill about that.”

He’s standing next to you in the bathroom, giving himself a once-over in the mirror. You’re impressed- maybe it’s because you’re going out today, but normally he couldn’t care less about how he looks. 

“k,” he shrugs, adjusting his hood and fluffing up the edges.

“I don’t hear a “promise”…” you say, warningly.

“and i don’t plan on givin’ ya one. you know you drive me crazy, no matter how long it’s been.” He flashes you a grin. You frown and cross your arms.

“Sans. I’m not letting you touch me until you promise me you’ll keep it under control.”

“oh, c’mon, angel…” he says, pleadingly. His hand hovers teasingly by the side of your face, and you bat it away.

“Nuh-uh. C’mon, lemme hear it.”

He sighs, rolling his eyelights.

“i promise i won’t do anythin’ crazy while we’re out.”

“Right. Maybe we can watch a movie or something when we get back in.”

You make sure to bump your hip against his when he pecks you on the cheek as extra incentive. You laugh to yourself as his face (quite literally) turns red. 

“If you’re that easy to get all flustered, maybe I should take the lead from now on, huh?”

A feral look flares in his eyelights, and his grin widens threateningly. You raise your eyebrows- he wouldn’t hurt you, though you know he very well could. This is his way of dominating, and you let him have it. You know that once he’s cooled off he’s just as strong as you are.

“oh, you get me. but f’you wanna play like that? i’ll show ya who’s the REAL boss here, angel,” he says, growling and roughly pulling you closer by the hips. 

Your turn to turn red. He laughs and lets you pull back slightly. 

“heh. knew it.”

“Yeah, yeah.”

When you feel him tickling his fingertips at the skin under your sweatshirt, you frown. 

“Please don’t.”

He backs off. You can get as ruffled and angry and stern as you want, but the only really effective tactic for you is to set boundaries. Because he respects them, at least when it comes to whether or not it affects you directly.

Some of your preferences weren’t like that. Like, “don’t scare the guys who try hitting on me in public.” To be fair, he’d earned that reprimand. He was proud of it, too. He’d scared quite a few jerks out of their cat-calling habits with a look and a threat. Or even just a look, on occasion. He… hadn’t exactly stopped doing that. He just did it when you weren’t around.

What you don’t know can’t hurt you.  
And angels have to keep their innocence.

“Thanks. Weather’s been weird, I just want to pretend like this is normal, ok?” Your words snap him out of his thoughts. “I promise, once we’re home we can do whatever, but- while we’re out we need to keep it cool.”

“gotcha.”

“You’re sure?”

“whatever you’re up for, angel.”

“Thank you.”

You stand on tip-toe to peck him on the mouth- he leans in and steals your little kiss eagerly. You have to smile. For someone so tough, he really has a thing for your lighter kisses.

“c’mon, we gotta go if we’re gonna hit all our stops today.”

“Oh- right, shopping. It’s just a few places, Target first.”

He sighs. Ugh. Target.

“I know it’s not your favorite, but we really need more of the good detergent. And milk.”

“alright, alright. let’s get goin’, then.”

~~~~~

Sans hates shopping, and he remembers why the moment he sets foot in Target.

There is truly an unfortunate amount of hot, young (probably single) people who work here. And these uniforms are by no means loose. At least, in comparison to his own basketball shorts and hoodie. He feels like they’re judging him when he walks in with you. HIM, the weird monster with the gold tooth and the low growl, with YOU.

Because he really calls you angel for a reason.

You almost seem to have a glow, a halo around you. And the way you walk, light on your feet and graceful, like you have wings. Your smile, and the way your eyes crinkle up at the edges… an angel with a real devil like him. Damn. He gets lost for a moment, just taking you in as he walks by you- only brought back when you speak.

“Hey, could you go grab the milk? No shortcuts though, we nearly gave that guy a heart attack last time.”

“deserved it, too…” he mutters. However, when you shoot him That Look, he sighs and heads towards the dairy aisle. 

He sees a few employees give him blatant looks of suspicion as the two of you separate. It’s a common rumor that monsters are prone to stealing things. He wished he could say that that was nothing but a rumor, and it had nothing to it. But, well, he’d been a bit of a thief himself before he met you. You’d seen that as a big no-no. Though, frankly, he had no idea why.

If you can get away with it, it’s legal, right? If nobody knows.

Guess that’s not how it works on the surface.

“Can I h-help you with anything, sir?”

He looks around when a young guy comes timidly up to him. He has “newbie” written all over his face, and when Sans looks around, he can see a few employees looking at him with pity.

Sans decides he likes this kid’s guts. 

“know where the milk is?” Sure, he already knows where it is, but he might as well give this poor kid a chance.

“Oh! Yeah, right this way!”

“sweet, thanks.”

Down one aisle, more and more strange looks from various people, aaaaaand… milk. Sans feels a bit odd that this kid had to escort him all the way here, but then again, that happens sometimes. And then again, this scrawny teenager has no idea who he’s dealing with. Too innocent. 

Sans realizes he might have a soft spot for innocence.

“Here you go! Um- is there anything else I can help you find?”

Sans grabs the carton with the red cap, like you told him to, checks the date, and shrugs.

“not really. just my wife, i guess. but, heh, that’s not really in your job description, is it?”

The kid goes starry-eyed.

“T-that lady you walked in with was your WIFE?”

“i’m just as surprised as you, kid,” he chuckles.  
“Man. You’re super lucky,” he says, still a little star-struck. Suddenly, a thought strikes him and he jolts. “But, uh, heh, that’s probably not very p-professional! Have a nice day!”

And he walks off, ears burning red. Sans just laughs and watches him go. Weird kid. Fun, but weird. You’re gonna get a kick out of this story. Speaking of you, he feels a ping come from his phone and looks down. 

(“little help on aisle seven”)  
(“full permission to scare this one off”)

He stiffens and feels all over the surrounding area for your soul. Once he gets a mark on it, he does a quick scan. It’s going a little faster than usual, and you’re incredibly uncomfortable. He shortcuts directly to your location. You jump when he appears, but soon relax in relief. Your hand goes up to find his, and you smile-

“Oh, heh, here he is now!”

The guy who seems to have been talking to you freezes, eyeing Sans up and down. Sans does the same. He tries to look as casually intimidating as possible (though honestly he doesn’t have to try) to this sleaze-bag. 

“Didn’t think you were, like, serious about having a monster husband,” he says, narrowing his eyes.

“welp, here i am,” Sans growls.

That, though, luckily seems to be enough to get him to back down. He shrugs and starts walking off, muttering under his breath.

“Must be pretty f*ckin’ desperate if you’re runnin’ after monsters…”

Both you and Sans tense at the same time. Sans more than you. But he doesn’t move this time. You do.

“Hey, wait,” you call, tapping the guy on the shoulder before he gets entirely out of the aisle. 

He turns around, raising his eyebrows- just in time your you to kick your leg up straight into his balls. He collapses immediately, yelling, and you lean over him, still shaking with anger.

“Any other comments you wanna make about me or my husband?”

He shakes his head ‘no’, trying to crawl away.

“You’re crazy! What the hell! I’m reporting you!”

“I’ll be right there to report you. Hitting on me even after I repeatedly asked you to stop, that’s called harassment.”

“F*ck you!”

“You wish.”

You turn back to Sans, who- well, this is the most star-struck you’ve ever seen him. You’ll handle that in the car.

“We’re leaving. You have the milk?”

He nods slowly and holds it up as if to show you. You sigh, laughing a little. You snag a bottle of detergent off the shelf and grab his free hand.

“C’mon, bonehead.”

The guy on the floor is gone now, which is surprising. You thought he’d be immobilized for at least a little longer than that. Whatever- if he reports you, you have a pretty good argument anyway. Though, looking back, maybe kicking him in the nuts was a bit extreme. 

You look at Sans as you pull him along beside you, confused. He’s normally either laughing or bubbling over with rage at this point. When he gets mad, he can be quite the fountain of death threats. But he’s just silent, looking at you like you’re the only person on the planet. It might just be your faulty vision, but you could have sworn his eyelights turned into hearts a few times when your eyes found his eyesockets. Geez. 

By the time you make it to the register, you can see the greasy-haired guy ranting to some poor employee, red in the face. When you come into his line of sight, he points and shouts wildly. Poor guy, having to deal with this creeps’ whining. Speaking of the employee, though, when he sees you, his face lights up happily. You wonder why, but try to stay busy paying for your things.

“We should get out of here before he tries arresting us,” you say, sarcastically, looking back at him.

Sans looks back too, though a bit more distractedly. You hear him laugh lowly, though you still don’t know why. Employee-guy and creep are crossing over to talk to you now- you tug on Sans’ hand. 

“I’m serious,” you say, trying to drag him out the door. He doesn’t move.

“chill out, angel, it’s gonna be fine.”

“Excuse me?”

Great- you turn to the employee (who actually looks a lot younger than you thought he was). Creep is crossing his arms, trying to puff out his chest but still guarding his nuts. You snort.

“U-um, this man was harassing you?”

“Hey! That’s not what I told you, idiot!”

Sans stiffens again.

“you really oughta redefine who ya think the idiot is here.”

“Shut the hell up, monster- that freaky lady just kicked me in the balls!”

“you call my wife a freak one more time-“

“Um, hold on.” the kid forces his way in between the two angry guys, holding his hands up politely. Sans backs off, however reluctantly, but the guy just looks like he’s about to get violent. “Firstly, sir, I’m sure she wouldn’t have attacked you without good reason. And, um, in fact, we’ve been warned about a guy with your description who comes into stores in the area and, um, harasses women.”

He pulls a small sheet of paper out of his front pocket, glances at it, and asks,

“Your name isn’t Wallace Left, is it?” 

“Doesn’t f*ckin’ matter.”

“I’m going to take that as a yes.”

“You little-“

“Anyhow, the cops have already been called, and security should be here any second.”

All the blood leaves- Wallaces- face, but soon it comes back, red and ruddy and angry. He raises a fist and tries to swing it at the kid, but Sans pulls both him and you behind him and out of the reach of the guy. 

You’re frankly surprised he hasn’t tried to punch anyone sooner. 

You look over at the kid, who is currently looking at Sans like he’s his new father. You have to laugh. He must be eighteen or nineteen, but he has so much wonder in his face you think he might be seven. He looks over at you next, then goes right back into professional mode-

“Sorry, ma’am.”

“Don’t worry about it. There have been ruder people.”

He just nods.

Wallace is looking at Sans, currently the only barrier between him and you- and the kid, and is getting angrier and angrier. Sans knows using magic on humans without their permission is a federal offense here, but that doesn’t mean he doesn’t want to. Blue magic could pin this little creep to the floor faster than you could say “hey, wait”. 

Luckily, security do that job for him, wrestling him to the floor while he yells. This is really making a scene now, you notice with a sigh. All you wanted was milk and detergent: is that honestly too much to ask? Honestly. Sans turns around to the two of you, grinning tiredly. 

“sorry ‘bout this, kid.”

“This is honestly the coolest thing that’s ever happened to me, so, no worries!”

“huh. hope you get some more interesting stuff later on than a creep like him.”

“Oh, I didn’t mean him. He’s terrible, they’ve been looking for him for a couple months, I think. Warned us about him a few days ago. He, um- he’s not very respectful? Scary. But, YOU,” he turns to you starry eyed. You fully expect some comment on your appearance or composure, but instead- “You’re, like, Natasha Romanoff!! You KICKED HIM IN THE BALLS!”

You laugh, blushing a little, embarrassed. 

“Uh- I mean- I guess I kind of draw the line at monster-human racism? Thank you?”

“I would too! I mean-“ he looks around when someone taps him on the shoulder to ask him some things. “Oh. Looks like I have to go. Have a nice day!”

As he walks away, he leans back and whispers-

“I’ll make sure to give you a good defense!”

You smile a little, then grab Sans’ hand and head towards the car.

“This grocery bag is cutting off circulation to my hand,” you comment, staring straight ahead.

“oh. want me to carry it for ya?“

“I LIKE it,” you say, a little bit of energy sparking your eyes. “I haven’t felt this alive since you showed me that tongue trick.”

He nearly stops walking- damn. You’re REALLY lighting him up right now. 

When that creep had first said the thing about you being desperate, and that’s why you were with Sans, he thought his soul was going to stop. He’d never thought about that before. And you tensed up- he could have sworn you did that under accusation. If Wallace was right about that, about you just taking what you could get, Sans thought he’d dust. 

It nearly killed him when you’d said, “hey, wait,” calling after him. You were going after someone else. Like he’d always thought you would, once you relieved you were too good for him. Too precious. Even after you married him, he thought you might just leave one day. You were walking away, asking him to wait for you-

he legitimately thought he was going to die.

And then- ha!- you’d swung your leg up and NAILED that loser. He didn’t exactly understand what you’d done to make that poor sap crumble so fast (probably one of those human weak spots you told him about) but goddamn if it wasn’t the hottest thing ever. 

You’d, you’d LEANED OVER HIM, that sweet smile on your face,

“Any other comments you’d like to make about me-“ and, this is the best part- “or my husband?”

You still acknowledged him. This wasn’t some revenge on your personal honor, this was about him, too. You cared. And you were literally willing to attack someone to prove it. His angel… had a dark side. He felt his soul pound so hard he thought it would break his f*cking ribcage.

“You’re crazy! What the hell! I’m reporting you!”

That had made him mad. Not only was he insulting you, but he clearly couldn’t see the display of perfection you were putting on. He should have considered himself HONORED he was allowed to see this. Allowed to see YOU like this. 

“I’ll be right there to report you. Hitting on me even after I repeatedly asked you to stop, that’s called harassment.”

Oh, boy.

“F*ck you!”

“You wish.”

OH, boy.  
He can’t wait until he’s home, he’s going to use that.

When you turned back to him, there might as well have been literal stars in your eyes. And you were a little flushed, still shaking with anger. If the old Sans saw this, he might have laughed at you. But then he just stood in awe of you. You really were an angel: but you were no longer down to earth.

In that moment, you were a goddess.

And you took him to the front, guided him like a child, still burning with anger. He could feel it coming off of your soul. It was electric. And now you’re on his arm, telling him that you feel ALIVE, and it’s sparking the air around you. He grins broadly, suddenly, and starts laughing. It starts low and quiet, but it builds until it’s uproarious and he bends over, cackling. 

“Sans, the car is just a little bit away, come on,” you giggle, pulling on his arm. His laughter is contagious.

“i love you so much,” he laughs. He’s running his hand over his skull and shaking his head. “so much, angel, you have no idea.”

That makes you smile, and you stop to boop your nose in between his eyesockets.

“Don’t ever believe the shit guys like that say, okay? I’m not,” you bristle again, and he can practically feel electricity crackling against his skull, “DESPERATE, or anything. I just have a thing for punny badass skeletons, I guess.”

“guess that means i gotta thing for pun-loving badass angels, then.”

“Pfft.”

He bumps forward for a quick kiss, nuzzles you gently, and continues walking. You follow- he’s not usually this… soft… with you- so you’re a bit surprised. Once you’ve unloaded your bag of groceries in the car and hopped in, you purse your lips.

“what’s that look for?” Sans asks, starting the car.

“I don’t want to run any more errands… I think we should just go home, okay?”

He grins broadly, pulls the car out of the parking space quickly, and starts home. You smile, still feeling that electric tingle of energy in you, but relaxed. It was like an adrenaline rush that washed up in you, and died down. 

“Is it possible for humans to have magic?” you ask, taking a breath and letting the feeling embrace you. 

“if any human out there does, it’s you, angel.”

“You think?” 

He grins, settling his eyelights on you. “i know.”

As he drives home, his hand crawls under your jacket and rubs your back.

You’re asleep before the car leaves the parking lot.

**Author's Note:**

> Thanks for reading!
> 
> I HAD A GOOD IDEA (maybe)  
> IMMA (try to) WRITE IT  
> MANY CHAPTERS (hopefully)  
> WE'LL SEE WHAT HAPPENS (if I dont do it or it takes a while im so sorry im sad ack)
> 
> Please leave comments~~ They're always good motivation, and I'll always respond!


End file.
